The present invention relates to a measurement condition setting fixture used in measurement of living body information for measuring living body information in a non-invasive manner, using transmitted light or reflected light obtained by irradiating a living body with light. In particular, the present invention relates to a measurement condition setting fixture, a measurement condition setting method, and a living body information measuring apparatus for setting measurement conditions, which include a site at which a measurement is to be taken and a relative position of the site at which a measurement is to be taken with respect to a measuring optical system, at desirable conditions at the time of measurement and for detaching the site at which a measurement is to be taken from the measuring optical system when no measurement is performed.
In general, in optical measurement for irradiating a living body with light and obtaining living body information based on transmitted or reflected light, even a slight change in the site irradiated by light at which a measurement is to be taken (hereinafter, referred to simply as a xe2x80x9cmeasurement sitexe2x80x9d) is a significant cause of error. Accordingly, in order to perform precise measurement, it is required to maintain measurement conditions such as the measurement site, the incident position and angle of light with respect to the measurement site, the position and angle at which the transmitted or reflected light from the measurement site is received, and the like.
In order to maintain the measurement conditions, it is ideal to keep the living body secured to the measuring apparatus throughout the measurement.
However, in the case where the living body is secured to the measuring apparatus, many inconveniences occur when the measurement takes a long time or a routine measurement is performed, such that the person undergoing the measurement cannot be away from the measuring apparatus or only one person can undergo the measurement by one measuring apparatus.
Moreover, since the surface of the living body is generally soft, repetition of attachment and detachment of the measuring apparatus with respect to the living body causes an error in the measurement conditions. For example, in the case where a method of using a clip-type measuring probe or a method of securing the measuring probe to the measurement site with a two-sided adhesive tape is used, the measurement site of the living body can be detached from the optical system of the measuring apparatus except when the measurement is performed. However, it is very difficult to accurately return to the previous location of the measurement site, i.e., to accurately attach the probe to the previous measurement site, in order to perform the measurement again.
As methods for accurately returning to the location of the measurement site, a method of marking the measurement site of the living body and visually determining the measurement site based on the marking, and a method of taking a pattern of the measurement site in advance and determining the measurement site using the pattern have been proposed. By either method, however, it is difficult to return to the location of the measurement site due to the softness of the living body. By the latter method, the same number of patterns as that of the measurement sites are required. In the case where the measurement site is deformed, the pattern cannot be used.
The present invention, which has been made under these circumstances, has the objectives of (1) providing a simple measurement condition setting fixture for easily and accurately setting measurement conditions, which include a measurement site and a relative position of the measurement site with respect to the measuring optical system, at desirable conditions at the time of measurement and for detaching the measurement site from the measuring optical system when no measurement is performed, and a measurement condition setting method utilizing the same, and (2) providing a living body information measuring apparatus for providing highly precise measurement values with little deviation.
A measurement condition setting fixture according to the present invention for setting measurement conditions including a positional relationship between a prescribed site of a living body and a measuring optical system at desirable conditions, in measurement of living body information including irradiating the prescribed site with light from the measuring optical system and obtaining living body information based on the light obtained from the prescribed site, the measurement condition setting fixture comprising a measurement site securing section attached to the prescribed site; and a measuring optical system securing section, to which a part of the measuring optical system is detachably attachable, for securing the part of the measuring optical system and the prescribed site in a prescribed positional relationship when the part of the measuring optical system is coupled to the measuring optical system, wherein the part of the measuring optical system is coupled to the measuring optical system securing section at the time of measurement, thereby realizing the desirable measurement conditions, and the part of the measuring optical system is detached from the measuring optical system securing section when no measurement is performed. Thus, the above-described objectives are achieved.
The part of the measuring optical system may include a light irradiation section for irradiating the prescribed site of the living body with light to be directed thereto, and the light irradiation section may be coupled to the measuring optical system securing section at the time of measurement, thereby securing the light irradiation section and the prescribed site in a prescribed positional relationship.
The part of the measuring optical system may include a light receiving section for receiving light which is obtained from the prescribed site of the living body, and the light receiving section may be coupled to the measuring optical system securing section at the time of measurement, thereby securing the light receiving section and the prescribed site in a prescribed positional relationship.
The measuring optical system securing section may have an opening, and the prescribed site of the living body may be inserted into the opening.
A measurement condition setting method according to the present invention for setting measurement conditions including a positional relationship between a prescribed site of a living body and a measuring optical system at desirable conditions using a measurement condition setting fixture, in measurement of living body information including irradiating the prescribed site with light from the measuring optical system and obtaining living body information based on the light obtained from the prescribed site; the measurement condition setting fixture including a measurement site securing section attached to the prescribed site, and a measuring optical system securing section, to which a part of the measuring optical system is detachably attachable, for securing the part of the measuring optical system and the prescribed site in a prescribed positional relationship when the part of the measuring optical system is coupled to the measuring optical system securing section, the measurement condition setting method comprising the steps of attaching the part of the measuring optical system to the measuring optical system securing section of the measurement condition setting fixture at the time of measurement, thereby realizing the desirable measurement conditions; and detaching the measuring optical system from the measurement condition setting fixture when no measurement is performed. Thus, the above-described objectives are achieved.
The part of the measuring optical system may include a light irradiation section for irradiating the prescribed site of the living body with light to be directed thereto, and the light irradiation section may be coupled to the measuring optical system securing section at the time of measurement, thereby securing the light irradiation section and the prescribed site in a prescribed positional relationship.
The part of the measuring optical system may include a light receiving section for receiving light which is obtained from the prescribed site of the living body, and the light receiving section may be coupled to the measuring optical system securing section at the time of measurement, thereby securing the light receiving section and the prescribed site in a prescribed positional relationship.
The measuring optical system securing section may have an opening, and the prescribed site of the living body irradiated by the light may be inserted into the opening.
A living body information measuring apparatus according to the present invention for irradiating a prescribed site of a living body with light and obtaining living body information based on the light obtained from the prescribed site, the apparatus comprising a measuring optical system for irradiating the prescribed site with light and receiving the light obtained from the prescribed site; a measurement condition setting fixture having a measurement site securing section attached to the prescribed site, and a measuring optical system securing section, to which a part of the measuring optical system is detachably attachable, for securing the part of the measuring optical system and the prescribed site in a prescribed positional relationship; an arithmetic operation processing section for performing an arithmetic operation on the living body information based on an intensity of the light obtained from the prescribed site and received by the measuring optical system; and an output section for outputting the living body information obtained as a result of the arithmetic operation, wherein the part of the measuring optical system is coupled to the measuring optical system securing section of the measurement condition setting fixture at the time of measurement, thereby setting measurement conditions including a positional relationship between the prescribed site of the living body and the measuring optical system at desirable conditions; and the measuring optical system is detached from the measurement condition setting fixture when no measurement is performed. Thus, the above-described objectives are achieved.
The part of the measuring optical system may include a light irradiation section for irradiating the prescribed site of the living body with light to be directed thereto, and the light irradiation section may be coupled to the measuring optical system securing section at the time of measurement, thereby securing the light irradiation section and the prescribed site in a prescribed positional relationship.
The part of the measuring optical system may include a light receiving section for receiving light which is obtained from the prescribed site of the living body, and the light receiving section may be coupled to the measuring optical system securing section at the time of measurement, thereby securing the light receiving section and the prescribed site in a prescribed positional relationship.
The measuring optical system securing section may have an opening, and the prescribed site of the living body may be inserted into the opening.
The measuring optical system may have an integrating sphere.
The measuring optical system may have an optical fiber.